Electric switch



Se-pt. 12, 1939. o, wlLMs 2,172,633

ELECTRIC SWITCH Filed Deo. 18,v 1957 5 Sheets-Sheet l G.. O. WILMS sept. 12, 1939.

ELEcTRIoswLTcH 3 Sheecs-Sheefl 5 F11-ed Dec. 18, 1937 Patented Sept. 12, 1939- 1 PATENT ori-"ics ELECTRIC SWITCH Gustav o. Wilms, Milwaukee, Wis., assigner to Allen-Bradley Company,` Milwaukee, Wis., a corporation of Wisconsin Application December 18, 1937, Serial No. 180,565 s claimsl (ci. zoo-16s) This invention relates to improvements in electric switches and refers particularly to control switches of the type' forming the subject matter of ReissuePatent No. 20,094 issued September 1st, 1936, to Gustav O. Wilms and Albert J. Dawe.

Where switches operate under severe service demands or on heavy duty, they are subject to considerable wear and may be rendered inoperative; and in many such instances interruptions 0 in service are costly. One such use is on conveyor lines of manufacturing plants where any break in the continuity of operation'seriously aiects the production of the plant. Another instance Where continuity of service is of extreme importance is in high speed production with punch presses, automatic screw machines, lathes and the like. Here every precaution must be taken to guard against the possibility of time consuming breakdowns.

2@ It is therefore customary to remove the defective or worn switch as quickly as possible, replace it with a new one and effect the necessary repairs to the removed switch when convenient.

With this objective in view, the invention has as one of its objectsl to provide an electric controller switch capable vof being substantially instantly disconnected .and connected in the circuitl with the lead wires whereby proper positioning of the parts during replacement' of the switch and rigidity in its securement are assured.

Another object of this invention is to provide smpliedmeans for establishing readily separable electrical connections between' the terminals of the switch per se and the terminals' to vwhich the wire leads are permanently attached so that upon replacement of a switch, good electrical connections between the wire leads and the switch terminals will be assured.

. Another object of this invention is to provide a switch for the -purpose described which is so constructed and designed that'the entire unit is mounted on a metal back plate by. which the switch may be mounted in its cabinet or directly on any other support withoutentailing insulation in the support.

With the above and other objects in View which will appear as the description proceeds, this invention resides in the novel construction, combination and-arrangement of parts substantially as hereinafter described, and more particularly defined by the appended claims, it being understood that such changes in the precise embodiment of the hereindisclosed invention may be made as come within the scope of the claims.

The accompanying drawings illustrate several complete examples of the physical embodiment of the invention constructed in accordance with the best modes so farfdevised for the practical application ofthe principles thereof, and in which:

Figure 1 is a front view of a switch constructed in accordance with this invention;

Figure 2 is a vertical sectional View taken through Figure 1 on the plane of the line 2 2;

Figure 3 is a perspective view of the switch illustrating the manner in which removal and replacement can be quickly effected;

Figure 4 is a vertical sectional view similar to Figure 2, illustrating a slightly modified embodiment of the invention;

Figure 5 'is a fragmentary vertical sectional view illustrating another modification; and

Figure 6 is a schematic view depicting the electrical connections employed'in the device.

Referring now particularly to the accompanying drawings in which like numerals indicate like parts throughout the several views, the numeral 5 designates a metal back plate upon which the entire switch is mounted. This back plate may be mounted in a cabinet or directly on any other desired support.

Fixed to the upper end portion of the back plate is an insulated terminal board f 6. This board is preferably formed of molded insulating material and projects forwardly from the back plate to overlie the insulated terminal head l of an electromagnetic switch, indicated generally by the numeral 8, secured to the lower portion of the back plate.

The terminal board 6 has a plurality of sets of terminals 9 and I0 mounted thereon, each provided with a screw Il by which wire leads I2 and I3 are connected to the terminals 9 and l0, respectively. Between each set of terminals thel board has upstanding ribs I4 which extend around the front edge of the board to provide insulating barriers between each set of terminals.

, and an amature 23 which carries the sets oi' instance they are secured in place by bolts I5.

It is to be observed that the terminal board has an opening I8 adjacent vto each of the terminals 9 and that the terminals 9 project upwardly from the terminal board, whereas the outer end portions of the terminals I0 project .downwardly around the front edge of the board. In each in stance, however, the screws I I by which the wire c leads are secured to the terminals face the front,

movable contacts 24.

T-he specic manner in which the movable contacts are mounted and the other details of the switch per se form no part of this invention, and consequently need not be described. It is sufilcient to note that the armature moves through the center of the magnet coil 25 and that the field piece 22 is xed to a frame 26 by which the entire switch is mounted on the back plate 5 and to which the insulated head Tis secured.

The contacts I1 and I8 are electrically connected to external terminals 21 and 28, respectively, located on the top of the insulated terminal head 1. The terminals 21 have upwardly projecting end portions adapted to pass through the openings I6 in the terminal board for engagement with the front faces of the terminals 9. The terminals 28 have downwardly projecting end portions disposed in pockets or recesses 29 formed in the front face of the insulated terminal head 1 to be engageable with the inner faces of the downwardly extending terminals I0.

The upwardly projecting terminals 21 and the downwardly projecting parts of the terminals I0 have their outer extremities bifurcated as at 30 to receive clamping screws 3l threaded in the terminals 9 and 28 to enable the engaging ter' minal portions to be securely clamped'together. In lthis manner readily separable electrical con# nections are established between the switch terminals and the terminals mounted on the terminal board. The switch is thus readily removable for replacements without entailing loosening of the Wire leads I2 and I3 byl which the switch is connected in an electrical circuit.

Ordinarily, the leads I2 constitute the power lines and the leads I3 are connected to an electrical translating machine adapted to be connected with the power lines upon closure of the switch.

Any suitable manner of readily detachably securing the switch to the back plate may be employed, and in the preferred embodiment of the invention illustrated in Figures 1; 2 and 3, the metal frame 26 of the switch magnet has outwardly directed flanges 33 which overlie the front face of the back plate, and have their lower end portions engageable in -back of hooks 34 struck forwardly from the back plate.

With this construction, the attachment of the switch requires merely the proper engagement of the bifurcated ends of the terminals with their clamping screwsi a slight upwardmovement to carryv tlie lower edges of the flanges 33 15a-$1? the w 2,172,633 to the board may be provided and in the present hooks, and then a downward motion to firmly engage the flanges in back of the-hooks.. Tighten. ing the screws al holds the switch in pmoe.

If desired, the separable electrical connection between the terminals on the switch and thoseV carriedby the terminal board may be made by spring clips, such as illustrated in the modified embodiments of the invention shown in 4 and 5. c

In the construction shown Ain Figure 4, thel 10 switch terminals have spring clips 3,5 riveted or otherwise fixed thereto. These clips extend -upwardly to engage the front faces. of the terminals 36 and 31 carried by the terminal board.- with this arrangement, it is preferable to havethe front terminalsg provided with upwardly. directed end portionsinwhich the screws II are threaded. -f

It is also preferable in this construction to secure the switch to the back plate by means of screws 38. I'hese screws rigidly hold the switch in place independently of the means employed to eiIect the electrical connections between the terminals. As the vscrews-38 are tightened the switch is drawn toward the back plate and consequentlyplace the spring clips l35 under tension.-

In the embodiment of the invention illustrated in Figure 5, the terminal board carries spring clips 39, each of which has a pair of lingers 40 yieldingly urged toward each other and between which a blade 4I carried by the switch head is insertable."

In other respects, the vconstruction of Figure 5 may be like that ot Figure 4. l

From the foregoing description token in oonnection with'l the accompanying drawings, it will K be readily apparent to those skilled 'in the art that this invention enables ready removal and replacement of control switches without entailing the aient in number to those on the head; a' fixed support mounting the terminal board in a substantially horizontal position; lead wires fastened to the terminals 'on the board; means readily detachably mounting the switch with its insulated head directly under the terminal board; and.- means for establishing a readily separable electrical connection between the terminals of the switch head and those of the terminal board upon mounting of the switch in position so that the switch is readily removable and replaceable without necessitating loosening of the wire leads.

2. In combination: an electromagnetic switch having an insulated head; terminals on the,ex' terior of the head for electricallyconnecting the switch in a circuit; a terminal boardyterminals' on said board; a iixed supporting paneto which the terminal board is secured; wire leads attached l `to the terminals on the board: meansfor' readily detachably mounting the switch in a. position Y.

with its head directly under the terminal board; and complementary means carried by the terminal board and the insulated head of the switch for establishing readily separable electrical connections between the terminals on the board and those on the insulated head of the switch upon mounting of the switch in position so that the switch is readily removable and replaceable withoutwardly therefrom to forni a ledge jutting out from the back plate; terminals carried by theboard and extending upwardly therefrom; the board having passages therethrough to permit access to the terminals from the underside of the board; means directly accessible from in iront of the terminal board for securing wire "leads to the terminals on the board; an' electromagnetic switch having a terminal carrying head at its top; connecting the switch in a circuit; means for readily detachably mounting the switch on the back plate with its terminal head under the ledge formed by the terminal board; and means carried by the terminal head of the switch electrically connected with its terminals and projecting upwardly therefrom to pass through said passages in the terminal boardl and electrically engage the terminals on the board for establishing readily separable electrical connections between the terminals on the board and the terminals of the switch upon proper mounting 'ofthe switch on the back plate so that the switch is readily removable and replaceable without *entailing looseningl of the wire leads.

4. In combination: a metal back plate adapted to be mounted in an upright position; an insulated terminal board iixed to the back plate and projecting substantially perpendicularly ktherefrom to form a ledge; terminals carried by the board; wire leads attached to the terminals; an

electromagnetic switch having an insulated ter- 'minal head at its top; switch terminals on said head for connecting the switch in an' electric cir- 0 ing head at its top;

cuit; means for readily detachably mounting the switch on the back plate with its insulated head directly under the ledge formed by the terminal board; and mutually engageable means carried by the terminal board and the terminal head of the switch for establishing-readily separable' electrical connections between the terminals of the switch and those of the board upon proper mounting of the switch on the back plate.

5. In combination': an upright metal back plate; a terminal board xed to the back plate and projecting forwardlyv therefrom to form a ledge; terminals on the board; wire leads secured to the terminals; an electromagnetic switch having a metal frame and an insulated contact carryterminals on the exterior of the head for connecting the switch in an electric circuit; mutually engageable means on the terminal board and insulated switch head foreffecting readily separable electrical connections between 55 the terminals of the switch andthose of the terminals mounted on said head for board, said'interengaging means holding the switch in a iixed position under the terminal board; and a readily detachable mechanical connection between the frame of the switch and the metal back plate cooperating with said interengaging means to readily removably secure the switch in position.

6. In combination: an upright metal supporting plate; two units,` each unit comprising insulation and electrical conducting terminals mounted thereon; means rigidly fastening one of said units to the metal plate near its top' and with said vunit projecting forwardly from the plate to iorm a ledge; and means removably securing the second unit to the plate in the space under the ledge formed by the first unit with certain of the terminals of the second unit engaging certain of the terminals of thev first unit.

7. In combination: a rigid back plate adapted to be mounted in an upright position; an insulated terminal board rigidly xed to said back plate and jutting outwardly therefrom to form a ledge; an electrical instrumentality readily removably mounted under 'said ledge, saidlelectrical instrumentality having a plurality of external terminals by which said instrumentality is connected in circuit;` other terminals permanently carried by the terminal board; lead Wires permanently connected .to said last named terminals; and readily separable electrical connectionsbetween the terminals of the electrical and the terminal board, whereby" removal and replacement of the electrical instrumentality may be quickly elected without necessitating loosening the wire leads.

8. In combination: a back plate; an insulated terminal headiixed to the back plate and jutting outwardly therefrom to form a ledge; an electrical instrumentality of a size to substantially t within the space in front of the back plate and under the terminal board, said electrical instrumentality having external terminals through which the instrumentality is connected in circuit; other terminals xed to the terminal board; Wire leads permanently connected with said last `named terminals; electrical connections lbetween the terminals on the board and the terminals of theelectrical instrumentality, said connections providing some V support for the electrical instrumentality; and a vreadily separable'connection between the electrical instrumentality and the back plate cooperating with said electrical connections in holding GUSTAV O. WILMS.

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